The present invention relates to computer systems, and more particularly to a method and system for allowing fault tolerance for power failures to be provided.
FIG. 1 depicts a conventional network 1 including a master computer system 5 and conventional computer systems 10, 20 and 30 that are chained together. Although only three conventional computer systems 10, 20 and 30 are shown, the conventional network 1 will typically include a larger number of conventional computer systems (not shown). In addition, although separately depicted, the master computer system 5 could be the same as one of the conventional computer systems 10, 20 and 30. The conventional computer systems 10, 20 and 30 each include a power supply 12, 22 and 32, respectively and a system load 14, 24 and 34, respectively. Each of the conventional computer systems 10, 20 and 30 also includes an input 16, 26 and 36, respectively and an output 18, 28 and 38, respectively. For clarity, only one input 16,26 and 36 and one output 18, 28 and 38 is shown. However, typically the inputs 16, 26 and 36 and the outputs 18, 28 and 38 include multiple pins.
The conventional computer systems 10, 20 and 30 are chained together in the network 1. Thus, the output 18 and 28 of one computer system 10 and 20, respectively, is coupled to the input 26 and 36, respectively, of the next computer system 20 and 30, respectively. The conventional computer system 10, which has its output 18 coupled to the input 26 of the conventional computer system 20, is considered to be upstream of the conventional computer system 20. The conventional computer system 30, which has its input 36 coupled to the output 28 of the conventional computer system 20, is considered to be downstream of the conventional computer system 20. A conventional computer system 10, 20 or 30 communicates upstream via its input 16, 26 or 36, respectively, and communicates downstream via its output 18, 28 or 38, respectively.
The conventional master computer system 5 can controls portions of the remaining conventional computer systems 10, 20 and 30. In addition, the conventional computer systems 10, 20 and 30 can communicate with each other. In order to provide these functionalities, the system loads 14, 24 and 34 are used to communicate with and redrive signals from other conventional computer systems in the conventional network 1. Thus, the system loads 14, 24 and 34 are connected to the inputs 16, 26 and 36, respectively, and to the outputs 18, 28 and 38, respectively. For example, the system load 24 can be used to redrive signals from the upstream conventional computer system 10 to the downstream conventional computer system 30 as well as to drive signals from the downstream conventional computer system 30 to the upstream conventional computer system 10. The signals driven by the system loads 14, 24 and 34 can include both data and commands to the conventional computer systems 10, 20 and 30, respectively.
For example, each of the conventional computer systems 10, 20 and 30 may have a keyboard, a mouse and a monitor (not explicitly shown in FIG. 1). The conventional master computer system 5 can control the keyboard, video and mouse of the remaining conventional computer systems 10, 20 and 30 in the conventional network 1. Each of the computer systems 10, 20 and 30 thus may receive and send keyboard, video and mouse (KVM) signals through their outputs 18, 28 and 38 and receive or send KVM signals through their inputs 16, 26 and 36, respectively. The system loads 14, 24 and 34 may be used to redrive the KVM signals. The conventional master computer system 5 can control the operation of the keyboard, the video played on the monitor and the mouse of each of the remaining conventional computer systems 10, 20 and 30 through the KVM signals.
Although the conventional network 1 functions, one of ordinary skill in the art will readily recognize that the conventional network 1 is subject to failure due to failures of the power supplies 12, 22 and 32. As shown in FIG. 1, the power supplies 12, 22 and 32 are coupled to and provide power to the system loads 14, 24 and 34, respectively. Without power, the system loads 14, 24 and 34 cannot function properly. If the power supply 12, 22 or 32 fails, the system load 14, 24 or 34, respectively, cannot redrive signals from another conventional computer system or from the conventional master computer system 5. As a result, all downstream computer systems will be cut off from the remainder of the network 1. This could cause a major failure of the conventional network 1. For example, if the power supply 32 fails, only the conventional computer system 30 will be affected. However, if the power supply 12 fails then all of the conventional computer systems 20 and 30 will be cut off from the conventional master computer system 5. Thus, the failure of a single system 10 could adversely affect virtually the entire network 1.
Accordingly, what is needed is a system and method for providing fault tolerances for power failures in a computer system in a network composed of chained computer systems. The present invention addresses such a need.
The present invention provides a method and system for providing computer system for use in a network having a plurality of computer systems linked in a chain. The method and system comprise providing a power supply, at least one input and at least one output for the computer system. The at least one input is for receiving power from a first portion of the plurality of computer systems and for providing power from the power supply to the first portion of the plurality of computer systems. The at least one output is for providing power from the power supply to a second portion of the plurality of computer systems and for receiving power from the second portion of the plurality of computer systems. In one aspect, the first portion of the plurality computer systems provides an upstream computer system and the second portion of the plurality computer systems includes a downstream computer system. In this aspect, the method and system also comprise providing an input power control circuit and a reverse current protection circuits for the computer system. The input power control circuit is coupled with the at least one input and is for controlling power provided to the computer system such that power is input to the computer system when the power supply does not function. According to the system and method disclosed herein, the present invention allows computer systems in a network to share power. Thus, the reliability of the network is improved.